The default bitnami configuration does not load any .htaccess file to the apache configuration. You can check the reason for this in this link.
You could try enabling them just to see if it helps. For that, you only need to change the following line:
in the file
If that does not help, I would try to contact the theme developers and ask them if they have seen this issue in the past.
Also, have you tried to log in from the page you have redirected?